Establishing a wear state of a cutting nozzle

ABSTRACT

Methods, systems, and devices for establishing a wear state of a cutting nozzle of a laser processing machine. An actual state of the cutting nozzle shape is established by a three-dimensional evaluation performed by a nozzle shape sensor and an associated controller. The established actual state of the cutting nozzle shape is compared to a desired state of the cutting nozzle shape, and the wear state of the cutting nozzle is established based on a result of the comparison.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to GermanApplication No. DE 10 2013 214 174.2 filed on Jul. 19, 2013. The contentof this priority application is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The specification relates to methods, systems, and devices forestablishing a wear state of a cutting nozzle of a laser processingmachine.

BACKGROUND

Cutting nozzles are used in laser cutting processes to achieve a uniformand high-quality cutting result. The shape of the cutting nozzle has adirect effect on the cutting gas flow and consequently directlyinfluences the cutting result. Consequently, wear of the cutting nozzlewhich typically occurs during the cutting process also has an influenceon the cutting result. The causes of wear of the cutting nozzle are, forexample, bonded slag and bonded splashes of the melt of the processedmaterial or burnouts resulting from sweeping or back-reflected laserradiation and direct or sweeping collisions of the cutting nozzle withthe workpiece or other components. Owing to such wear, the shape of thecutting nozzle can change in such a manner that the flow relationshipsat the cutting nozzle also vary. This causes in particular a change ofthe flow cross-section and consequently the preferred direction of thegas flow. The negative consequence of this is, for example, a cuttingresult which varies in accordance with the direction, such as, forexample, beard deposits of different extents on the workpiece.Furthermore, the above-mentioned causes of wear also influence themeasurement of the spacing between the cutting nozzle and the workpieceto be processed during the laser cutting process in a negative manner.

In order to counteract the negative consequences of the causes of wear,it is known for an operator to examine the cutting nozzle manually.However, this requires time-intensive and cost-intensive idle times ofthe laser processing machine. In addition, the respective operators haveto have the relevant experience to be able to carry out the examinationin a reliable manner.

SUMMARY

Described below are methods, systems, and devices for establishing awear state of a cutting nozzle of a laser processing machine.

One aspect of the invention features a method that includes establishingthe wear state of the cutting nozzle by a three-dimensional cuttingnozzle shape of the cutting nozzle, to increase and improve the methodreliability and the method quality during a laser cutting operation.

The wear state established using the three-dimensional cutting nozzleshape can contain depth information relating to the three-dimensionalshape of the cutting nozzle, that is to say, information relating to thedepth profile of the cutting nozzle or, in other words, the topographyof the cutting nozzle and consequently a substantially more preciseassessment of the cutting capacity of the cutting nozzle is possible.The more precise assessment extends in particular to the influence ofthe wear-related three-dimensional change of the cutting nozzle shape onthe cutting gas flow during operation. Owing to the detection of thethree-dimensional cutting nozzle shape, it is advantageously possible,for example, to quantify indentations, discharges or adhesions on thecutting nozzle and to allow them to be incorporated in the establishmentof the wear state of the cutting nozzle. The wear state of cuttingnozzles can be assessed in a relatively objective manner. Based on theestablished wear state, whether or not a nozzle change is required canbe assessed.

As used herein, the term “cutting nozzle shape” refers to the entiretopography of a cutting nozzle, that is to say, the entirethree-dimensional surface geometry of the cutting nozzle, including thegas channel, the cutting front, the nozzle outer cone, etc. The term“wear state” refers to a deviation of the three-dimensional cuttingnozzle shape from the original state thereof (the desired state).

Preferably, the wear state is further established by the actual state ofthe cutting nozzle shape determined by means of a three-dimensionalevaluation being compared with a desired state of the cutting nozzleshape. In order to determine the actual state of the cutting nozzle, athree-dimensional actual shape of the cutting nozzle (for example, inthe manner of CAD data) as an actual state can be calculated or derived,for example, from one or more camera exposures of a camera device, bymeans of the three-dimensional evaluation. The actual shape calculatedin this manner can subsequently be compared with the desired shape ofthe cutting nozzle (for example, also in the manner of CAD data). Fromthe deviation of the actual shape from the desired shape or thedeviation of the actual state from the desired state, the wear state cansubsequently be determined. The desired shape or the desired state canbe predetermined and stored in memory of an evaluation unit.

The three-dimensional cutting nozzle shape is preferably detected in acontact-free manner, for example, by means of optical measurement of thecutting nozzle topology. The information relating to thethree-dimensional cutting nozzle shape, that is to say, relating to thedepth profile of the cutting nozzle, can be detected, for example,optically by means of a confocal microscope.

A preferred variant of the method includes illuminating the cuttingnozzle using an illumination device, recording the illuminated cuttingnozzle using a camera device, and establishing the wear state of thecutting nozzle by evaluating the camera exposure recorded. In order todetect the three-dimensional cutting nozzle shape, the illuminationdevice and the camera device are arranged relative to each other in sucha manner that the wear state is established using information whichrelates to the cutting nozzle shape and which is obtained by means ofthree-dimensional evaluation of the camera exposure. The wear stateestablished in this manner, owing to the three-dimensional evaluation ofthe camera exposure, also contains the depth information relating to thethree-dimensional cutting nozzle shape.

The detection of the three-dimensional cutting nozzle shape ispreferably carried out using one or more of the following differentillumination variants:

On the one hand, the cutting nozzle can be illuminated by theillumination device with structured light, in particular using thelight-section method. By means of illumination with structured light,the three-dimensional cutting nozzle shape for the camera device can bemade detectable for three-dimensional evaluation. It is possible to useas structured light, for example, one or more lines (light-section) or apoint (triangulation) or pseudo-randomly distributed point clouds(random pattern method) for illumination and to observe them at atriangulation angle. Preferably, the three-dimensional surface shape ofthe cutting nozzle is recorded by the camera device by means of one ormore light section(s) which is/are incident at a triangulation angle andwhich is/are projected onto the cutting nozzle as an illumination line.Owing to continuous detection of the depth profile along the lightsection, with simultaneous lateral movement of the cutting nozzlerelative to the measurement device, the 3D topography of the cuttingnozzle (the depth profile) can be detected in a continuous manner. Theobservation by the camera device can be carried out in this instance,for example, perpendicularly relative to the cutting nozzle or thecutting nozzle front, and the illumination can be carried out by meansof the illumination device at an acute angle. Alternatively, theillumination can also be carried out, for example, by means of theillumination device perpendicularly relative to the cutting nozzle andthe observation by the camera device can be carried out at an acuteangle relative thereto. In principle, the camera device may be arrangedor orientated with the optical axis thereof and/or the illuminationdevice with the optical axis thereof at any angles relative to thecutting nozzle or the cutting nozzle front. In this instance, theScheimpflug angle between the objective lens and the camera device canbe taken into consideration for correct imaging when the monitored Zposition (depth information) changes. The triangulation angle istypically defined as the angle between the observation direction and theillumination direction.

On the other hand, the cutting nozzle can be illuminated by theillumination device in the manner of incident-light darkfieldillumination. In this instance, by means of lateral illumination of thecutting nozzle, only recesses or projections on the cutting nozzle areilluminated.

In a further illumination variant, the cutting nozzle can be illuminatedby means of an illumination device which is arranged in the cuttingnozzle longitudinal axis in the manner of incident-light brightfieldillumination. In a preferred variant of the incident-light brightfieldillumination, the cutting nozzle is illuminated by the illuminationdevice from an angular range which substantially corresponds to thenumerical aperture of the camera device or is smaller than the numericalaperture of the camera device. Owing to the compliance with this angularrange, the cutting nozzle is illuminated almost perpendicularly with ahigh beam quality so that regions of the cutting nozzle surface whoseorientation does not permit any reflection of the illumination into thecamera device, appear darker than regions of the cutting nozzle surfacewhose orientation enables a direct reflection into the camera device.Consequently, the recognition and evaluation of recesses and/orprojections of the cutting nozzle shape are also possible.

The three-dimensional cutting nozzle shape is at the same timepreferably detected by at least two of the illumination variants whichare selected from the group comprising: illumination in thelight-section method, illumination in the manner of incident-lightdarkfield illumination or illumination in the manner of incident-lightbrightfield illumination. Owing to the combination of at least two ofthe illumination variants according to the invention, even more preciseassessment of the cutting capacity of a cutting nozzle which has beensubjected to wear can be achieved. Of course, the illumination variantsaccording to the invention can also be combined with a two-dimensionalevaluation of the cutting nozzle.

In some implementations, the three-dimensional cutting nozzle shape isdetected by scanning the cutting nozzle. The scanning can take place,for example, using mechanical means in a tactile manner (usingneedle-like scanning elements). Alternatively, the scanning can also becarried out in a contactless manner using electrical, in particularcapacitive, means.

Preferably, the three-dimensional shape of the cutting nozzle front isdetected. In this manner, particularly precise establishment of the wearstate is possible since the influence of the wear-related change ingeometry of the cutting nozzle is particularly evident on the cuttinggas guide, that is to say, the flow relationships at the cutting nozzle,and consequently the cutting capacity of the cutting nozzle.

Another aspect of the invention features a laser processing machineincluding a laser processing head having a cutting nozzle arrangedthereon and a sensor unit for detecting a three-dimensional cuttingnozzle shape of the cutting nozzle, with an evaluation unit programmedto establish a wear state of the cutting nozzle using thethree-dimensional cutting nozzle shape.

Other advantages and advantageous embodiments of the subject-matter ofthe invention will be appreciated from the description, the claims andthe drawings. The features mentioned above and those set out below mayalso be used individually per se or together in any combination. Theembodiments shown and described are not intended to be understood to bea conclusive listing but are instead of exemplary character fordescribing the invention. The Figures of the drawings show thesubject-matter according to the invention in a highly schematic mannerand are not intended to be understood to be to scale.

DESCRIPTION OF DRAWINGS

FIGS. 1 a, 1 b are a cross-section and a front view of a cutting nozzle,respectively.

FIG. 2 is a cutting nozzle which is illuminated using the light-sectionmethod.

FIG. 3 is a cutting nozzle which is illuminated in the manner ofdarkfield illumination.

FIG. 4 is a cutting nozzle which is illuminated in the manner ofbrightfield illumination.

In the following description of the drawings, identical referencenumerals are used for components which are the same or which have thesame function.

DETAILED DESCRIPTION

The cutting nozzle 1 shown in FIGS. 1 a, 1 b is used for laser cuttingof workpieces. The cutting nozzle 1 has a cutting nozzle shape 2 whichis characterised by a three-dimensional surface geometry and which isdelimited inter alia by a cutting front 3 of the cutting nozzle 1, anozzle outer cone 4 of the cutting nozzle 1 and a gas channel 5 of thecutting nozzle 1.

During the laser cutting, defects on the cutting nozzle 1 occur,typically as a result of wear. A first wear-related defect of thecutting nozzle 1 may be a three-dimensional defect location 6 in thecutting nozzle material, such as, for example, burnouts resulting fromsweeping or back-reflected laser radiation or scratches as a result ofcollisions of the cutting nozzle 1 with the workpiece. Anotherwear-related defect may be a three-dimensional material deposit 7 on thecutting nozzle front 3, such as, for example, bonded slag or splashes ofthe molten mass of the processed workpiece material. Furthermore,narrowings 8 of the geometry of the gas channel 5, which have beenbrought about, for example, by collisions of the cutting nozzle 1 withthe workpiece or other components, or burnouts 9 of the gas channel 5may also be wear-related defects of the cutting nozzle 1. All thedefects described above constitute changes in the original cuttingnozzle shape 2 which may have a negative influence on the laser cuttingprocess depending on the current state of wear. This is because thedefects, on the one hand, change the flow relationships at the cuttingnozzle 1, so that a uniform cutting result is generally no longerachieved and, on the other hand, they also impair the detection of thespacing between the cutting nozzle 1 and the workpiece, which detectionis relevant for controlling the cutting process.

FIG. 2 shows a laser processing machine 10 having a laser processinghead 11 which has a cutting nozzle 1 according to FIG. 1 and a sensorunit 12 for detecting the three-dimensional cutting nozzle shape 2. Thesensor unit 12 comprises an illumination device which is constructed asa laser 13 for producing a laser light-section 16 for illuminating thecutting nozzle 1, a camera device 14 for recording the illuminatedcutting nozzle 1 and an evaluation unit 15. In order to establish thecurrent wear state of the cutting nozzle 1, a method is carried out inthe following manner.

In order to detect the three-dimensional cutting nozzle shape 2, inparticular in order to detect the three-dimensional shape of the cuttingnozzle front 3, the cutting nozzle 1 is illuminated in a first methodstep by means of the laser 13 using the light-section method. To thisend, the light section 16 is produced by the laser 13 and projected ontothe cutting nozzle 1 at a so-called triangulation angle α (for example,at α=45 degrees), so that an illumination line which is in the form of alaser line appears on the cutting nozzle 1. In order to detect thethree-dimensional cutting nozzle shape 2, the laser 13 and the cameradevice 14 are arranged in a corresponding manner with respect to eachother, that is to say, the camera device 14 is arranged with the opticalaxis 17 thereof at an angle of 90 degrees with respect to the cuttingnozzle front 3 and the laser 13 is arranged at the triangulation angle αwith respect to the cutting nozzle front 3 or the cutting nozzle 1. Inanother method step, the illuminated cutting nozzle 1 is recorded bymeans of the camera device 14, that is to say, the projected laser lineis recorded by the camera device 14. Then, in another method step, thewear state of the cutting nozzle 1 can be established by the cameraexposure recorded being evaluated in a three-dimensional manner, that isto say, by information relating to the three-dimensional cutting nozzleshape 2 being obtained from the camera exposure or being calculated bymeans of image processing.

From the camera exposures, based on the known triangulation angle α asinformation relating to the three-dimensional cutting nozzle shape 2, itis possible to calculate in a trigonometric manner the Z coordinates(that is to say, the coordinates perpendicular relative to a cameraimage plane) of all the points along the laser line. The evaluation unit15 is programmed, using this three-dimensional evaluation of the cameraexposure, to obtain the information relating to the three-dimensionalcutting nozzle shape 2 (in particular the Z coordinates) and toestablish the wear state based on this information. Owing to thecalculated information relating to the three-dimensional cutting nozzleshape 2 (for example, in the form of the three-dimensional coordinates),the actual state of the cutting nozzle shape 2 can be established andcompared with a desired state of the cutting nozzle shape 2. Based onthe comparison between the actual state and the desired state,conclusions can be drawn relating to the (current) wear state of thecutting nozzle 1. If the wear state established exceeds a predeterminedor permissible value, a cutting nozzle change may be initiated.

The determination of the wear state is established in particular basedon the three-dimensional defect locations 6 in the cutting nozzlematerial and/or based on the three-dimensional material deposits 7 atthe cutting nozzle 1 and/or based on the geometry of the cutting nozzlegas channel 5. These defect locations 6, material deposits 7 andgeometry changes 8, 9 constitute deviations of the actual state from thedesired state. In order to establish the wear state based on thegeometry of the cutting nozzle gas channel 5, it is possible to use, forexample, the size of the diameter of the gas channel 5 or the roundnessthereof. Deviations from the original size of the diameter or from theoriginal desired geometry may occur, for example, owing to collisionswith workpieces or the above-described rejects and adhesions. In orderto detect the complete three-dimensional cutting nozzle shape 2, thesensor unit 12 and the cutting nozzle 1 are arranged so as to be able tobe displaced relative to each other, in particular in a direction 18parallel with the cutting front 3. Consequently, owing to relativemovements of the laser line projected by the laser 13 in relation to thecutting nozzle 1, the entire cutting nozzle shape 2 can be travelled anddetected.

In the laser processing machine 10 illustrated in FIG. 3, in order toilluminate the cutting nozzle 1, two illumination devices 19 which areconstructed as an incident-light darkfield illumination unit areprovided. Accordingly, in a method for detecting the three-dimensionalcutting nozzle shape 2, in the first method step the cutting nozzle 1 isilluminated by the illumination device 19 in the manner ofincident-light darkfield illumination. To this end, the cutting nozzle 1is illuminated with lateral illumination cones 20 which are directedonto the cutting nozzle 1 at an incident angle β of approximately 15degrees with respect to the plane 21 of the cutting nozzle front 3 andpreferably surround the cutting nozzle 1. The illumination devices 19and the camera device 14 are accordingly arranged with respect to eachother for this purpose, that is to say, the camera device 14 is arrangedwith the optical axis 17 thereof at an angle of approximately 90 degreeswith respect to the cutting nozzle front 3 and the illumination devices19 are arranged with their optical axes 22 at the angle β=15 degreeswith respect to the plane 21 of the cutting nozzle front 3. Thethree-dimensional defects and occurrences of unevenness (recesses 6 orprojections 7) which deviate from the plane 21, are thereby visible inthe incident-light darkfield. In the case of the incident-lightdarkfield illumination, the illumination cones 20 are orientated in sucha manner that the radiation reflected directly from the cutting nozzle 1does not strike the camera device 14 but instead only radiation which isredirected on the occurrences of unevenness (for example, scattered,bent or refracted radiation) reaches the camera device 14. In the nextmethod step, the cutting nozzle 1 which is illuminated in this manner isrecorded by the camera device 14 and the wear state is established bymeans of information which relates to the cutting nozzle shape 2 andwhich is obtained by means of three-dimensional evaluation of the cameraexposure. When the incident-light darkfield camera exposures areevaluated by the evaluation unit 15, illuminated regions can beextracted, for example, by means of a static or dynamic threshold valueor an edge detection algorithm (for example, Canny).

FIG. 4 finally shows a laser processing machine 10 in which, in contrastto the previous Figures, an illumination device which is constructed asan incident-light brightfield illumination unit (for example, as a diodelaser) 23 and which is arranged in the cutting nozzle longitudinal axis24 is provided in order to illuminate the cutting nozzle 1. In a methodfor detecting the three-dimensional cutting nozzle shape 2, in a firstmethod step the cutting nozzle 1 is at least partially illuminated bythe incident-light brightfield illumination 23 from an angular range(perpendicular with a high beam quality) which substantially correspondsto the numerical aperture of the camera device 14. In order to detectthe three-dimensional cutting front 3, both the incident-lightbrightfield illumination 23 and the camera device 14 are mutuallyarranged for this purpose with their optical axes 17 at 90 degrees withrespect to the cutting nozzle front 3. At the cutting nozzle 1, defectsand occurrences of unevenness which have been formed by wear, inparticular defects present on the cutting nozzle front 3 whoseprojections or recesses deviate from the perpendicularly illuminatedplane 21 of the cutting nozzle front 3, reflect the illumination lightnot directly back to the camera device 14 but instead at least partiallyin directions which can no longer be detected by the camera device 14.In the camera exposure of the illuminated cutting nozzle 1 recorded inthe next method step, the three-dimensional defects consequently appeardark (or darker) and therefore differ from the planar (or defect-free)cutting front 3. In the last method step, the wear state can beestablished by means of the information which relates to the cuttingnozzle shape 2 and which is obtained by means of the three-dimensionalevaluation of the camera exposure. In order to evaluate the cameraexposures and to establish the wear state, an evaluation unit 15 is alsoprovided.

In contrast to what is shown in the Figures, the three-dimensionalcutting nozzle shape 2 can at the same time be detected by means of atleast two of the above-described illumination variants, that is to say,the sensor unit 12 of the laser processing machine 10 may, for example,have a single camera device 14 for the light-section illumination andthe darkfield illumination or a camera device 14 for the light-sectionillumination and a camera device 14 for the darkfield illumination andan illumination device for the light-section illumination 13 and anillumination device for the darkfield illumination 19. Owing to thesimultaneous (or parallel) observation using different illuminationvariants, the precision of the establishment of the wear state of thecutting nozzle 1 can be further increased.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. A method of establishing a wear state of acutting nozzle of a laser processing machine, the method comprising:establishing an actual state of the cutting nozzle shape by depthinformation of the cutting nozzle performed by a nozzle shape sensor andan associated controller, the nozzle shape sensor including anillumination device and a camera, wherein establishing the actual stateof the cutting nozzle shape comprises: illuminating the cutting nozzleby the illumination device with structured light including one or morelines, one or more points, or both; recording data representing an imageof the illuminated cutting nozzle using the camera; and evaluating therecorded data to establish the actual state of the cutting nozzle shapeusing the associated controller, and wherein the illumination device andthe camera are arranged relative to each other, such that the actualstate of the cutting nozzle shape is established using informationobtained by a three-dimensional evaluation of the recorded data;comparing the established actual state of the cutting nozzle shape witha desired state of the cutting nozzle shape using the associatedcontroller; and establishing the wear state of the cutting nozzle basedon a result of the comparison using the associated controller.
 2. Themethod of claim 1, further comprising: recording digital datacorresponding to the actual state of the cutting nozzle shape using thenozzle shape sensor; and performing the three-dimensional evaluationbased on the recorded digital data using the associated controller. 3.The method of claim 1, wherein comparing the established actual state ofthe cutting nozzle shape with a desired state of the cutting nozzleshape comprises: digitally comparing data representing the establishedactual state of the cutting nozzle shape with stored data representingthe desired state of the cutting nozzle shape.
 4. The method of claim 1,wherein establishing the wear state of the cutting nozzle comprisesestablishing the wear state based on at least one of three-dimensionaldefect locations in cutting nozzle material, three-dimensional materialdeposits on the cutting nozzle, and a geometry of a cutting nozzle gaschannel.
 5. The method of claim 1 wherein the illumination device andthe camera are arranged relative to each other such that the structuredlight illuminating the cutting nozzle is observed by the camera at atriangulation angle between the illumination direction and theobservation direction, and wherein the camera is arranged with anoptical axis perpendicular to a front of the cutting nozzle, and theillumination device is arranged at the triangulation angle with respectto the front of the cutting nozzle.
 6. The method of claim 1, whereinilluminating the cutting nozzle comprises illuminating the cuttingnozzle by the illumination device in a manner of incident-lightdarkfield illumination.
 7. The method of claim 6, wherein illuminatingthe cutting nozzle comprises directing a lateral illumination cone fromthe illumination device onto the cutting nozzle, and wherein theillumination device and the camera are arranged such that a firstradiation reflected directly from the cutting nozzle bypasses the cameraand a second radiation reflected by an occurrence of unevenness isintercepted by the camera.
 8. The method of claim 1, wherein theillumination device is arranged along a longitudinal axis of the cuttingnozzle in a manner of incident-light brightfield illumination.
 9. Themethod of claim 8, wherein illuminating the cutting nozzle comprisesilluminating the cutting nozzle by the illumination device from anangular range that substantially corresponds to a numerical aperture ofthe camera or is smaller than the numerical aperture of the camera. 10.The method of claim 1, wherein establishing the actual state of thecutting nozzle shape comprises detecting a three-dimensional cuttingnozzle shape simultaneously using at least two of illumination in amanner of a light-section method, illumination in a manner ofincident-light darkfield illumination, and illumination in a manner ofincident-light brightfield illumination.
 11. The method of claim 10,wherein recording data representing the image of the illuminated cuttingnozzle comprises using the camera to record data corresponding to eachof light-section illumination and darkfield illumination.
 12. The methodof claim 1, wherein establishing the actual state of the cutting nozzleshape comprises establishing a three-dimensional shape of a front of thecutting nozzle.
 13. A laser processing machine comprising: a laserprocessing head having a cutting nozzle arranged thereon; and a sensorunit for detecting depth information of the cutting nozzle, the sensorunit having an evaluation unit running code configured to establish awear state of the cutting nozzle based on the depth information of thecutting nozzle, wherein the sensor unit includes an illumination devicefor illuminating the cutting nozzle with structured light including oneor more lines, one or more points, or both and a camera for recordingdata representing an image of the illuminated cutting nozzle, andwherein the evaluation unit is configured to perform a three-dimensionalevaluation of the recorded data to obtain information of the depthinformation of the cutting nozzle and to establish the wear state basedon the obtained information.
 14. The laser processing machine of claim13, wherein the sensor unit and the cutting nozzle are arranged suchthat the sensor unit and the cutting nozzle can be moved relative toeach other to detect a three-dimensional cutting nozzle shape.
 15. Themethod of claim 1, further comprising: continuously detecting the depthinformation along a laser light-section including the one or more linesusing the nozzle shape sensor, with simultaneous lateral movement of thecutting nozzle relative to the nozzle shape sensor.
 16. The method ofclaim 1, wherein the structured light comprises pseudo-randomlydistributed point clouds for illumination.
 17. The laser processingmachine of claim 13, wherein the structured light comprisespseudo-randomly distributed point clouds for illumination.
 18. The laserprocessing machine of claim 13, wherein the illumination device isconstructed to include one of: an incident-light darkfield illuminationunit, and an incident-light brightfield illumination unit.
 19. The laserprocessing machine of claim 14, wherein the sensor unit is configured tocontinuously detect the depth information along a laser light-sectionincluding the one or more lines with simultaneous lateral movement ofthe cutting nozzle relative to the sensor unit.